1. Field of the Invention
The present invention relates to a vehicle lighting actuating apparatus in which a vehicle electric discharge lamp such as a head light, or the like, is mounted.
2. Description of the Related Art
In an electric discharge lamp such as a metal halide lamp, or the like, used as a head light, electrodes of the electric discharge lamp are detachably attached to an electric discharge lamp socket held in the front portion of a vehicle so that electromotive power is supplied through a terminal of the socket. In the case of a head light, a high voltage of 13 kV or more is applied to the electric discharge lamp. Therefore, a voltage of about 400 V is boosted by a transformer to generate a high voltage at an output end of a secondary coil and it is connected to a terminal of a socket to thereby apply a voltage to the electric discharge lamp. In such a configuration, conventionally, the lighting transformer is provided outside a lamp housing in which an electric discharge lamp socket is provided and a high-voltage cable connected to the secondary coil output end of the lighting transformer is introduced into the lamp housing and connected to the terminal of the socket.
In the aforementioned conventional configuration, the disposed socket and the transformer are separately provided and connected to each other through a high-voltage cable. Accordingly, because the number of constituent parts increases, mounting of those parts is troublesome. There are further various problems that the high-voltage cable becomes an obstacle to design of the arrangement; electromagnetic wave is generated around the high-voltage cable to cause the maloperation of an electronic control circuit provided in a vehicle; voltage loss is generated because of the high-voltage cable; and the like.
Therefore, a vehicle lighting actuating apparatus has been proposed which comprises: a body case constituted by a transformer receiving portion, and a socket projected from one side surface of the transformer receiving portion for receiving a vehicle electric discharge lamp; and a lighting transformer received in the transformer receiving portion of the body case and including a core box having an iron core portion, a coil bobbin formed from an electrically insulating material and fitted onto the iron core portion, a secondary coil wound on the outer circumference of the coil bobbin and having a high voltage output end lead out from a wiring hole formed in the iron core portion and connected to terminals provided in the socket, and a primary coil electrically connected to an external electric path directly or indirectly through a circuit portion.
Further, a vehicle lighting actuating apparatus has been proposed which comprises: a body case constituted by a transformer receiving portion, and a socket projected from one side surface of the transformer receiving portion for receiving a vehicle electric discharge lamp; and a lighting transformer received in the transformer receiving portion of the body case and including a core box having an iron core portion, a coil bobbin formed from an electrically insulating material and fitted onto the iron core portion, a secondary coil wound on the outer circumference of the coil bobbin and electrically connected to terminals provided on the socket, and a primary coil wound on the circumference of the iron core portion and electrically connected to an external electric path directly or indirectly through a circuit portion.
In such a configuration, the body case having the transformer receiving portion, and the socket integrated with the transformer receiving portion is used so that the lighting transformer and the terminals of the socket are connected to each other in the inside of the body case. Accordingly, there arises an advantage that not only a single structure is obtained but also the high-voltage cable connecting the lighting transformer and the socket is unnecessary.
Further, in such a configuration, in order to facilitate electrical connection of the terminal of the socket to the high-voltage output end of the secondary coil of the lighting transformer, a configuration has been proposed in which: a connection tube portion is formed in the center of the coil bobbin so as to pierce the iron core portion so that the inside of the connection tube portion is used as a wiring hole and that the connection tube portion is made to coincide with the center of the socket; and a high-voltage output end of the secondary coil is led out to the wiring hole so as to be connected to the connection terminal of the socket.
The socket is preferably located substantially in the center position of the body came in order to secure a stable mounting form in the lamp housing. If the lighting transformer T is held in the center of the body case C as shown in FIG. 13, a space s surrounding the lighting transformer T in the housing C is, however, divided into two, upper and lower parts. Accordingly, the space for receiving a wiring member such as a printed-wiring substrate, or the like, cannot be secured sufficiently even by using the space s, so that not only one part of the space s is unsatisfactory but also the other part of the space s in which no wiring member is received is wasteful.
On the other hand, if the lighting transformer T is biased to one of the upper and lower sides with respect to the body case C as shown in FIG. 14, the space s to receive the wiring member can be secured sufficiently in the other side. Because the socket D is, however, eccentric with respect to the body case C, design of arrangement in the lamp housing becomes troublesome. Further, because the outer circumference of the socket D may project from the housing, the external appearance of the vehicle lighting actuating apparatus is distorted so that the design of arrangement thereof becomes more and more troublesome.